Water from high pressure zone of volute could re-enter impeller. In order to prevent this a physical separation between high and low pressure side is provided. Wear ring provides a flow restriction in order to prevent water from entering impeller again.

The overflow channel is connected to combined sewer through siphon. At crest level of siphon an air pipe is provided to activate siphon when water will reach in combined sewer at a stipulated level and is called siphon spillway.

A normal leakage rate is 20-60 drops of seal water/min. If it is below 20 drops of seal water/min n operator should gradually loosen packing gland nuts. He should observe leakage rate after loosening gland.

The road way to pumping station must be an all-wear roadway. The road way must be provided on a hard surface. Muddy roads lead to inconvenience during rainy season.

Centrifugal pumps can pump liquids which are of low viscosity. It cannot handle liquids such as oil. The liquid that is pumped by centrifugal pumps should be free from air.

For smaller sewers that are of pipe diameter less than 0.9 m, spacing given in between manholes is 45 m. In case of pipe diameter of sewers greater than 2 m, spacing is 300 m.

The internal dimension for a sewer of depth less than 0.9 m is 0.9 m * 0.8 m. The internal dimension for a sewer for depth between 0.9 m to 2.5 m is 1.2 m* 0.9 m, 1.2 m diameter for circular.

Pumping stations are used for a variety of infrastructures such as supply of water to canals, drainage of low-lying land and removal of sewage to processing sites.

Booster pumps are used to furr boost pressure in a system. It may be in-line circulator, horizontal split case, or vertical turbine in a can type of pump. Chopper Pumps are designed to chop up solids and stringy material as it pumps.

There are two types of basic pumps. One is centrifugal pump and or one is positive displacement pump. Centrifugal pump is also called as a roto-dynamic pump. These two pumps behave very differently with respect to flow rates and pressure head.